flywheel 0.2.1

SQLAlchemy-style ORM for Amazon's DynamoDB

Flywheel

Master Build:

0.1 Build:

0.2 Build:

Documentation:

http://flywheel.readthedocs.org/

Downloads:

http://pypi.python.org/pypi/flywheel

Source:

https://github.com/mathcamp/flywheel

Object mapper for Amazon’s DynamoDB

Getting Started

This is what a basic model looks like (schema taken from this DynamoDB API documentation)

from flywheel import Model, Field, GlobalIndex

class GameScore(Model):
    __metadata__ = {
        'global_indexes': [
            GlobalIndex('GameTitleIndex', 'title', 'top_score')
        ],
    }
    userid = Field(hash_key=True)
    title = Field(range_key=True)
    top_score = Field(data_type=int)
    top_score_time = Field(data_type=datetime)
    wins = Field(data_type=int)
    losses = Field(data_type=int)

    def __init__(self, title, userid):
        self.title = title
        self.userid = userid

Create a new top score:

>>> score = GameScore('Master Blaster', 'abc')
>>> score.top_score = 9001
>>> score.top_score_time = datetime.utcnow()
>>> engine.sync(score)

Get all top scores for a user:

>>> scores = engine.query(GameScore).filter(userid='abc').all()

Get the top score for Galaxy Invaders:

>>> top_score = engine.query(GameScore).filter(title='Galaxy Invaders')\
...     .first(desc=True)

Atomically increment a user’s “wins” count on Alien Adventure:

>>> score = GameScore('Alien Adventure', 'abc')
>>> score.incr_(wins=1)
>>> engine.sync(score)

Get all scores on Comet Quest that are over 9000:

>>> scores = engine.query(GameScore).filter(GameScore.top_score > 9000,
...                                         title='Comet Quest').all()

Changelog

0.2.1

• Breakage: Certain queries may now require you to specify an index where it was auto-detected before

• Feature: Queries can now filter on non-indexed fields

• Feature: More powerful “sync-if” constraints

• Feature: Can OR together filter constraints in queries

All changes are due to an update in the DynamoDB API

0.2.0

• Breakage: Engine no longer accepts boto connections (using dynamo3 instead)

• Breakage: Removing S3Type (no longer have boto as dependency)

• Feature: Support Python 3.2 and 3.3

• Feature: .count() terminator for queries

• Feature: Can override throughputs in Engine.create_schema()

• Bug fix: Engine namespace is truly isolated

0.1.3

• Bug fix: Some queries fail when global index has no range key

0.1.2

• Bug fix: Field names can begin with an underscore

• Feature: Models have a nice default __init__ method

0.1.1

• Bug fix: Can call incr_() on models that have not been saved yet

• Bug fix: Model comparison with None

0.1.0

• First public release